1. Field of the Invention
An aspect of this disclosure relates to a substrate processing apparatus and a film deposition apparatus.
2. Description of the Related Art
A contact structure is a type of multilayer interconnection structure where contact holes are formed in an interlayer insulating film between a lower wiring layer and an upper wiring layer to connect the upper and lower wiring layers. In the contact structure, for example, a metallic material such as aluminum, tungsten, or copper is embedded in the contact holes. On the inner surface of each contact hole, a barrier film of, for example, titanium nitride (TiN) is formed to prevent the metallic material from being diffused into the interlayer insulating film.
To form such a barrier film on the inner surface of a contact hole, for example, an atomic layer deposition (ALD) method or a molecular layer deposition (MLD) method may be used. In an exemplary process of forming a TiN film using such a deposition method, a titanium tetrachloride (TiCl4) gas is supplied to a semiconductor wafer (hereafter, simply referred to as “wafer”) so that Ti molecules are adsorbed on the wafer, and then an ammonia (NH3) gas is supplied to the wafer to nitride the Ti molecules and thereby form a TiN molecular layer. The TiCl4 gas and the NH3 gas (reaction gases) are alternately supplied to the wafer repeatedly to stack TiN molecular layers.
An exemplary apparatus for such a film forming process may include a processing chamber, a turntable provided in the processing chamber and on which a wafer is to be placed, process areas where reaction gases are supplied to the wafer on the turntable, and a separating area provided between the process areas in the rotational direction of the turntable and where a separation gas is supplied. In the apparatus, as the turntable rotates, the wafer sequentially passes through the process areas where the reaction gases are supplied. The wafer is heated while the turntable is rotated so that the reaction gases in the process areas are activated by heat energy received from the wafer, and adsorption and nitriding of molecules thereby occur as described above.
Here, there may be cases where the reaction gases spread in the processing chamber and are unable to receive sufficient heat energy, and where the reaction gases are diluted by the separation gas. If such problems occur, Ti molecules may not be adsorbed on the wafer or may not be sufficiently nitrided and as a result, a TiN film with desired quality may not be obtained.
Japanese Laid-Open Patent Publication No. 2011-100956 discloses a film deposition apparatus including a flow regulating part. The flow regulating part includes a base that covers the upper and side surfaces of a gas nozzle, and flow regulating plates protruding from the lower end of the base in the upstream and downstream directions of rotation of a turntable (may be referred to as “rotationally-upstream and rotationally-downstream directions”). However, in JP2011-100956, there is no mention about the distance in the rotationally-upstream direction from the side surface of the gas nozzle to a wall of the flow regulating part. If the distance is small, the pressure of the reaction gas below the gas nozzle increases, and the reaction gas flows in the rotationally-upstream direction and flows over the flow regulating part together with the separation gas. Accordingly, there is a demand for an apparatus that can increase the density of a reaction gas in a process area and thereby reliably process a substrate.